diff --git a/src/os_unixx.h b/src/os_unixx.h
index edf7914..8a456c2 100644
--- a/src/os_unixx.h
+++ b/src/os_unixx.h
@@ -17,12 +17,12 @@
 # define signal sigset
 #endif
 
-   /* Sun's sys/ioctl.h redefines symbols from termio world */
+   // Sun's sys/ioctl.h redefines symbols from termio world
 #if defined(HAVE_SYS_IOCTL_H) && !defined(SUN_SYSTEM)
 # include <sys/ioctl.h>
 #endif
 
-#ifndef USE_SYSTEM	/* use fork/exec to start the shell */
+#ifndef USE_SYSTEM	// use fork/exec to start the shell
 
 # if defined(HAVE_SYS_WAIT_H) || defined(HAVE_UNION_WAIT)
 #  include <sys/wait.h>
@@ -44,7 +44,7 @@
 #  endif
 # endif
 
-#endif /* !USE_SYSTEM */
+#endif // !USE_SYSTEM
 
 #ifdef HAVE_STROPTS_H
 #ifdef sinix
@@ -69,12 +69,12 @@
 #endif
 
 #ifdef HAVE_SYS_SYSTEMINFO_H
-/* <sys/systeminfo.h> uses SYS_NMLN but it may not be defined (CrayT3E). */
+// <sys/systeminfo.h> uses SYS_NMLN but it may not be defined (CrayT3E).
 # ifndef SYS_NMLN
 #  define SYS_NMLN 32
 # endif
 
-# include <sys/systeminfo.h>	/* for sysinfo */
+# include <sys/systeminfo.h>	// for sysinfo
 #endif
 
 /*
@@ -96,16 +96,16 @@
 #endif
 
 #ifdef HAVE_SYS_PTEM_H
-# include <sys/ptem.h>	/* must be after termios.h for Sinix */
-# ifndef _IO_PTEM_H	/* For UnixWare that should check for _IO_PT_PTEM_H */
+# include <sys/ptem.h>	// must be after termios.h for Sinix
+# ifndef _IO_PTEM_H	// For UnixWare that should check for _IO_PT_PTEM_H
 #  define _IO_PTEM_H
 # endif
 #endif
 
-/* shared library access */
+// shared library access
 #if defined(HAVE_DLFCN_H) && defined(USE_DLOPEN)
 # if defined(__MVS__) && !defined (__SUSV3)
-    /* needed to define RTLD_LAZY (Anthony Giorgio) */
+    // needed to define RTLD_LAZY (Anthony Giorgio)
 #  define __SUSV3
 # endif
 # include <dlfcn.h>